What do you call a disgusting mixture you don't want to drink?

What do you call a drink (usually an alcoholic one, say a long drink or a cocktail) that you don't want to have, because you consider it a low quality, disgusting mixture, maybe even of suspicious, unclear origins?

Infamous drinks like the sponge (drops of shots spilled on the counter all night, then collected with a sponge, squeezed into a glass and sold to the undemanding, or some poor homeless guys) could be an example here. Or your friend's first, experimental cocktail... :-)

Context: I want to reject a drink that I don't like, so I reply humorously and a bit sarcastically:

No, thanks. I don't want any of this ____?

Swill.

http://www.merriam-webster.com/dictionary/swill

swill noun. food for animals (such as pigs) made from scraps of food and water

food or drink that is very bad or unappealing

eg.

What is this swill?! I'm not drinking that!

I'd typically call such a drink a a weird concoction. Per Merriam-Webster (via Google Definition):

concoction: a mixture of various ingredients or elements. synonyms: *mixture, brew, preparation, potion *

Slop: ( from TFD)

• Unappetizing watery food or soup.

• Often, slops. The dirty water or liquid refuse of a household.

Slop Monster : ( from The Urban dictionary)

• When an otherwise sane, normal girl drinks too much alcohol and transforms into a stumbling, word slurring, wardrobe malfunctioning all around hot mess.

  • Please don't let me drink tequila tonight, unless you want the Slop Monster to rear its ugly head.